JPS60255883A - Self-adhesive sheet - Google Patents

Abstract

PURPOSE:To provide a self-adhesive sheet which shows strong adhesion of an adhesive to a base sheet and is suitable as plaster, etc., prepd. by forming a layer of an adhesive consisting of a diene polymer on a vinyl chloride resin base sheet by use of a specified adhesive resin compsn. CONSTITUTION:An adhesive resin compsn. is prepd. by mixing 1pt.wt. (A) at least one resin selected from among vinyl chloride resin (e.g. vinyl chloride/vinyl acetate copolymer) and thermoplastic resin which is compatible therewith (e.g. polymethyl methacrylate) with 1/6-6pts.wt. (B) diene copolymer (e.g. styrene/ butadiene or styrene/isopropylene block copolymer). The self-adhesive sheet is prepd. by forming a layer of a self-adhesive consisting of a diene copolymer over a vinyl chloride resin sheet (e.g. PVC sheet) by use of the adhesive resin compsn.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pressure-sensitive adhesive sheet, and more specifically, a pressure-sensitive adhesive sheet made of a diene copolymer is firmly adhered to a vinyl chloride-based resin base sheet, and is suitable for use as a patch, for example. This invention relates to a usable adhesive sheet.

Adhesive sheets are used for various purposes, for example,
BACKGROUND OF THE INVENTION Patch medicines made by laminating an adhesive containing drugs such as skin irritants and anti-inflammatory analgesics on a base sheet are used for medical purposes. For example, as described in JP-A No. 54-138124, such patch medicines not only have good adhesiveness and elasticity when applied to the skin, but also have good adhesiveness and elasticity when removed from the skin. It is known that diene copolymers are suitable as adhesives because they can be easily peeled off without irritating the adhesive, and diene block copolymers are particularly suitable.

On the other hand, for the above-mentioned patches, vinyl chloride resin is suitable as the base sheet because it is flexible and blends well with the skin. Particularly in patch drugs, diene copolymers contain higher fatty acids and liquid paraffin as plasticizers along with drugs, so they have poor affinity with vinyl chloride resin base sheets. As a result, when a patch is prepared by simply applying an adhesive onto a base sheet, there is a problem in that the adhesive properties of the adhesive to the base sheet are poor.

The present invention has been made in view of the above, and an object of the present invention is to provide a pressure-sensitive adhesive sheet in which a pressure-sensitive adhesive made of a diene copolymer is firmly adhered and laminated on a vinyl chloride-based resin base sheet. do.

In the adhesive sheet according to the present invention, the adhesive comprising a diene copolymer on a vinyl chloride resin base sheet is at least one type selected from the group consisting of a vinyl chloride resin and a thermoplastic resin having compatibility therewith. 1 part by weight of the resin and 1/6 to 6 parts by weight of the diene copolymer are laminated and bonded via an adhesive resin composition.

In the present invention, the vinyl chloride resin forming the base sheet is a vinyl chloride homopolymer or copolymer, such as polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, vinyl chloride-ethylene copolymer, chloride The resin composition includes a vinyl-propylene copolymer, etc., and necessary plasticizers, stabilizers, etc., but is preferably a resin composition made by blending a polyvinyl chloride homopolymer with necessary plasticizers, stabilizers, etc. It is a thing. Various plasticizers and stabilizers can be used without particular limitation, as long as they are commonly used for the above-mentioned vinyl chloride resins. However, as mentioned above,
In the case of a patch consisting of a pressure-sensitive adhesive made of a diene copolymer laminated and bonded onto a base sheet made of a vinyl chloride-based resin, a polyester plasticizer, which is a polymeric plasticizer, is preferably used as the plasticizer. It will be done. The thickness of the base sheet is also not particularly limited, but is usually 0.08 to 0.1
It is 2 ms.

In the present invention, the diene copolymers constituting the adhesive include polybutadiene, polyisoprene, styrene-based copolymers,
Examples include butadiene copolymer, styrene-isoprene copolymer, and the like. These diene copolymers may be used alone as adhesives, or may be used together with diene copolymers as a composition containing a plasticizer, tackifying resin, filler, anti-aging agent, etc. . Furthermore, as in the case of the above-mentioned attached medicine, it may contain necessary medicines. In addition, when the adhesive sheet according to the present invention is used as a patch, as described above, it not only has good adhesiveness and elasticity when applied to the skin, but also does not irritate the skin when applied to the skin. As the adhesive, a diene block copolymer such as a styrene-butadiene block copolymer or a styrene-isoprene block copolymer is preferably used because it can be easily peeled off without causing any damage.

Such block copolymers are disclosed, for example, in the above-mentioned Japanese Patent Application Laid-Open No.
As described in detail in Japanese Patent No. 4-138124, it is already known that A is a block of a glassy or hard inelastic thermoplastic polymer such as styrene or methylstyrene, and B is a block of a glassy or hard inelastic thermoplastic polymer such as butadiene or isoprene. When used as a block of an elastic polymer of conjugated diene, it is a diene block copolymer having an ABA structure, and block A accounts for 10 to 50% by weight of the total polymer weight. Such styrene-butadiene block copolymers are commercially available as Cariflex TR-1101, TR-1102, etc., and styrene-isoprene block copolymers are commercially available as Cariflex TR-1107 (both manufactured by Shell Chemical Co., Ltd.). and can be obtained.

In the pressure-sensitive adhesive sheet according to the present invention, the pressure-sensitive adhesive made of the diene copolymer as described above contains at least one resin selected from the group consisting of a vinyl chloride-based resin and a resin compatible therewith.
In the production of a pressure-sensitive adhesive sheet according to the present invention, the pressure-sensitive adhesive sheet is laminated and bonded onto a vinyl chloride resin base sheet via an adhesive resin composition comprising a mixture of a thermoplastic resin and a diene copolymer. This adhesive resin composition is prepared by dissolving this in a predetermined mixed solvent as a primer composition, applying this onto a base sheet and drying it, and then applying an adhesive thereon and drying it. Attach the adhesive to the

Here, the vinyl chloride resin in the adhesive resin composition is the same as the vinyl chloride resin as the base sheet.
In addition to vinyl chloride homopolymers, vinyl chloride-vinyl acetate copolymers, vinyl chloride-ethylene copolymers, etc. are used. Further, as a thermoplastic resin having compatibility with these vinyl chloride resins, for example, polymethyl methacrylate is preferably used, but polyurethane, polychloroprene rubber, etc. can also be used. In particular, a mixture of a vinyl chloride-vinyl acetate copolymer in which the degree of polymerization of vinyl chloride is 400 to 1,300 and a vinyl acetate content of 5 to 20%, and polymethyl methacrylate having a molecular weight of 500 to 2,000 is used as vinyl chloride. It is preferably used as a resin.

As the diene copolymer in the adhesive resin composition,
The same copolymer as the adhesive is preferably used. In particular, from the viewpoint of patch medicine, the adhesive is the above-mentioned diene block copolymer, and the diene copolymer in the adhesive resin composition is also used as the adhesive. The diene block copolymer is preferably the same as the diene block copolymer. In particular, the diene block copolymer has the advantage that it can be heated and melted and coated on a vinyl chloride resin base sheet. However, the vinyl chloride resin in the base sheet and the diene copolymer in the adhesive do not necessarily have to correspond to the vinyl chloride resin and diene copolymer in the adhesive resin composition, respectively.

In the present invention, in order to form strong adhesion between the vinyl chloride resin base sheet and the pressure-sensitive adhesive made of the diene copolymer, the diene copolymer is added to the chloride resin composition in the adhesive resin composition. It is necessary that the amount is in the range of 1/6 to 6 parts by weight per 1 part by weight of the vinyl resin or a resin compatible therewith.

Therefore, the primer composition used in the present invention preferably includes (8) 5 to 30 parts by weight of the vinyl chloride resin or a resin compatible therewith, (b) 5 to 30 parts by weight of the diene copolymer. and (C) (a) 30 to 45% by weight of an aromatic hydrocarbon that is a good solvent for the diene copolymer, and (b) a good solvent for the diene copolymer and the aromatic hydrocarbon It consists of 30-45% by weight of a lower fatty acid alkyl ester which is more volatile than hydrocarbons, and (1) 210-40% by weight of a lower alkyl ketone which is a good solvent for the vinyl chloride resin and is highly volatile. It consists of 40 to 90 parts by weight of a mixed solvent.

Here, as the aromatic hydrocarbon binder 7, for example, benzene, toluene or xylene is preferably used, as the lower fatty acid alkyl ester, for example, ethyl acetate, and as the lower alkyl ketone, for example, methyl ethyl ketone is preferably used.

Aromatic hydrocarbons are good solvents for diene-based copolymers, and lower alkyl ketones are good solvents for vinyl chloride-based resins, but if a mixed solvent of only these is used, the primer composition cannot be used as a solvent for vinyl chloride-based resins. When applied to a sheet, the aromatic hydrocarbon tends to remain even after heating and drying, so strong adhesion between the base sheet and the diene copolymer pressure-sensitive adhesive cannot be achieved. However, when the primer composition contains a lower fatty acid alkyl ester which is a good solvent for both vinyl chloride resin and diene copolymer and is highly volatile as described above, Coupled with the fact that the lower alkyl ketone, which is a good solvent, is also highly volatile, when the primer composition is applied onto the base sheet and dried by heating, it dries quickly without any residual solvent, and the PVC-based This enables strong adhesion between the resin base sheet and the diene copolymer adhesive.

The amount of the primer composition applied onto the vinyl chloride resin base sheet is preferably 20 to 60 g/rd, and then heated and dried at a temperature of about 120°C. The amount of diene copolymer applied as an adhesive on the base sheet depends on the intended use of the resulting adhesive sheet, but in the case of attached medicines, the thickness is usually 0.5 A range of 211 to 211 is preferable, and usually about 1 per prize.

As described above, according to the adhesive sheet of the present invention, the vinyl chloride resin and the diene copolymer are firmly adhered to each other, which was difficult to do in the past, and it can be suitably used as a medicinal patch, for example. I can do it.

The present invention will be explained below with reference to Examples.

Example 12 parts by weight of an equal weight mixture of vinyl chloride-vinyl acetate copolymer and polymethyl methacrylate, styrene-butadiene block copolymer Califlex TR-1101
) and 70 parts by weight of a solvent consisting of an equal weight ratio mixture of toluene, methyl ethyl ketone and ethyl acetate.

This primer composition was mixed with 100 parts by weight of polyvinyl chloride, 50 parts by weight of polyester plasticizer, 3 parts by weight of Ca-Zn stabilizer, and other appropriate amounts of necessary additives. After coating on the base sheet at a rate of 30 g/rd, it was heated and dried at a temperature of 120°C. Next, the same diene block copolymer as above was melt-coated onto this to a thickness of IB and cooled to obtain a pressure-sensitive adhesive sheet according to the present invention.

This adhesive sheet was left under constant temperature and humidity conditions of 50°C and 95% RH, and was removed every day and immediately rubbed with a finger on the adhesive surface to evaluate the ease of peeling the adhesive. It was confirmed that the adhesive was also firmly attached to the base sheet on the edge of the blade.

On the other hand, for comparison, a primer composition was prepared by dissolving 30 parts by weight of an equal weight ratio mixture of vinyl chloride-vinyl acetate copolymer and polymethyl methacrylate in 70 parts by weight of the same mixed solvent as above. A pressure-sensitive adhesive sheet was obtained in the same manner as above. As a result of evaluating this in the same manner as above, the adhesive was easily peeled off from the base sheet after only one day.

Claims (2)

[Claims] (1) An adhesive made of a diene copolymer is formed on a vinyl chloride resin base sheet by weight of at least one resin selected from the group consisting of vinyl chloride resins and thermoplastic resins having compatibility therewith. parts, diene copolymer 1
1. A pressure-sensitive adhesive sheet characterized in that it is laminated and bonded via an adhesive resin composition comprising: /6 to 6 parts by weight. (2) The adhesive sheet according to claim 1, wherein the diene copolymer is a diene block copolymer.